Ecological Studies on Some Agarophytes from Veraval Coast (India) I. Effects of Aerial Conditions on the Biomass Dynamics

Murthy, M. S. R.; Ramakrishna, T.; Rao, Y. N.; Ghose, Dipanjan

doi:10.1515/botm.1989.32.6.515

Cited by 12 publications

(5 citation statements)

References 20 publications

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“…Le suivi du cycle biologique d'Hypnea musciformis récoltée en milieu naturel, dans les deux stations d'étude, montre deux périodes de croissance active : la première en été et la seconde de moindre importance en automne. Ce cycle présente beaucoup de similitudes avec le cycle biologique de plusieurs autres espèces récoltées dans les mêmes sites : Gracilaria multipartita [30,31], Gigartina pistillata [10], Gymnogongrus patens [32], Gelidium sesquipedale [33,34] [18], l'intensité lumineuse [7], l'humidité de l'air [39], l'adaptation au substrat (plantes hôtes ou parasitisme) et la possibilité de prédation par les herbivores [40]. Ce dernier auteur suspecte que les populations d'Hypnea musciformis sont broutées par les amphipodes et les mollusques (Aplysia) [6] le taux de croissance de l'espèce en conditions contrôlées est élevé (20 %.j -1 ) et le meilleur rendement est observé lorsque la température de l'eau de mer est comprise entre 18 et 24°C couplé à une agitation en flux continu et à un supplément en nitrates et phosphates.…”

Section: Discussionunclassified

Croissance et capacité reproductive d’<i>Hypnea musciformis</i> (Rhodophyceae, Gigartinale) de la côte atlantique marocaine

Mouradi¹,

Chikhaoui²,

Mohamed³

et al. 2010

Afrique Science: Revue Internationale Des Sciences Et Technologie

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Growth and reproductuive capacity of Hypnea musciformis (Rhodophyceae, Gigartinale) on the Moroccan Atlantic coast Carrageenan producing seaweeds represent an important biomass along the Atlantic coast of Morocco and are exported as raw material without any local transformation, while agar industry is well developed in the country. The aim of the present work is the valorisation of the more abundant seaweeds and their local transformation. Hypnea musciformis is one of the species studied in the laboratory and a potential applicant for exploitation. The first step before exploitation is to gather information about the biology and growth of this species in natural environment or under controlled conditions in the laboratory. The seasonal growth and reproductive ability of this species have been studied during 2 years on two different locations of Moroccan Atlantic coast. The species was fertile almost all along the year and tetrasporophyte phase predominated. H. musciformis has 2 periods of active growth: the first one at the beginning of summer and the second one, less active, in autumn. The biological cycle is under the influence of different environmental factors as light, temperature, salinity position of the thallus on the seashore and acclimatization response of the seaweed to different habitats.

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Section: Discussionunclassified

Croissance et capacité reproductive d’<i>Hypnea musciformis</i> (Rhodophyceae, Gigartinale) de la côte atlantique marocaine

Mouradi¹,

Chikhaoui²,

Mohamed³

et al. 2010

Afrique Science: Revue Internationale Des Sciences Et Technologie

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“…Os resultados obtidos confirmaram a existência da sinergia entre os fatores ambientais (Murthy et aL 1989,;Faccini 1998)_ As biomassas de H musciformis variaram nas três áreas (ANOVA, p<0,001), não havendo padrão sazonal comum aos três locais_ Resultados semelhantes foram obtidos em populações no Estado de São Paulo (Faccini 1998). Observou-se que um mesmo fator ambiental causou interferência diferenciada no crescimento desta alga de acordo com o local de coleta.…”

Section: Discussionunclassified

Variação espaço-temporal de populações de Hypnea musciformis (Rhodophyta, Gigartinales) na baía de Sepetiba e Armação dos Búzios, RJ, Brasil

Reis

Yoneshigue‐Valentin

1998

Acta Bot. Bras.

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RESUMO -(Variação espaço-temporal de populações de Hypnea musciformis (Rhodophyta, Gigartinales) na baía de Sepetiba e Armação dos Búzios, RJ, Brasil). Três populações de Hypnea musciforlllis foram analisadas ao longo do Estado do Rio de Janeiro; duas epifíticas, sublitorãneas, localizadas na baía de Sepetiba (município de Mangaratiba) e uma epilítica, litorânea, localizada em praia exposta a mar aberto (praia Rasa, município de Armação de Búzios). Essas populações foram analisadas quanto à produção de biomassa, flora acompanhante e as possíveis interações com alguns fatores ambientais. As biomassas de H. musciformis variaram nos três locais, não havendo padrão sazonal comum. Observou-se que a movimentação de água, insolação, flora acompanhante e a relação entre a epífita e o hospedeiro, Sargassum spp., causaram efeitos diferenciados sobre a produção das biomassas nas diferentes populações.Palavras chave -Hypnea musciformis, carragenófita, sazonalidade, biomassa ABSTRACT -(Spatial and temporal variation ofpopulations of Hypnea musciformis (Rhodophyta, Gigartinales) in the Sepetiba bay and "Armação dos Búzios", RJ, Brazil). Three populations of H. musciformis were analyzed throughout Rio de Janeiro State; two sublittoral epiphytic populations located in the Sepetiba bay (Mangaratiba municipality), and one intertidal epilithic population on the shore facing the open sea (Rasa beach, Armação dos Búzios municipality). These populations were analyzed for seasonality in biomass production, the accompanying flora species, and the possible interactions with some environmental factors. The biomass production of H. lIluscifonnis was different at each site, water movement, sunlight, accompanying flora, and the relation between the epiphyte and host, Sargassum spp., caused different effecls on biomass production in differenl populations.

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“…Lawson 1966, Banaimoon 1988, Murthy et al 1989in Hong Kong, Williams 1994, Williams & Morritt 1995, Kaehler & Williams 1996, Nagarkar & Williams 1999. The relative impact of herbivory is also seasonally variable in the Hong Kong mid-intertidal zone (Williams 1993b).…”

Section: Seasonal Patternsmentioning

confidence: 99%

“…Hot summers kill foliose macroalgae and invertebrates, freeing primary space, and mobile species retreat lower on the shore and take refuge in crevices (Lawson 1966, John et al 1992, Kaehler & Williams 1996, Nagarkar & Williams 1999. In winter, conditions ameliorate, macroalgae flourish and mobile invertebrates extend their vertical range and their foraging periods (Banaimoon 1988, Murthy et al 1989, Williams & Morritt 1995. The structuring role of spatial heterogeneity and environmental harshness can, therefore, vary temporally on such seasonal tropical shores.…”

Section: Introductionmentioning

confidence: 99%

Primary succession on a seasonal tropical rocky shore: the relative roles of spatial heterogeneity and herbivory

Williams¹,

Davies²,

Nagarkar³

2000

Mar. Ecol. Prog. Ser.

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Hong Kong is within the tropics and has a seasonal climate. In winter, shores support patches of ephemeral macroalgae and areas of seemingly bare rock close to crevices where molluscan herbivores are abundant. Using a factorial design of herbivore exclusions in areas far and close to crevices, the development of algal assemblages was monitored in mid-shore, cleared areas, in winter. To estimate the role of herbivore mucus deposition, half the treatments received a mucus application. Algal development was estimated from macroalgal and biofilm development and chlorophyll a levels. In all areas, biofilms (diatoms, unicellular cyanobacteria) developed rapidly in herbivore exclusions followed by ephemeral macroalgae (Enteromorpha spp. and Porphyra suborbiculata). In herbivore access treatments, however, the algal assemblage was influenced by treatment location; few macroalgae developed in areas close to crevices, and the rock was dominated by cyanobacteria. A negative relationship between macroalgae and biofilms suggested that ephemeral algae were competitively dominant. In areas distant from herbivore refuges, ephemeral macroalgae did develop, illustrating that the effectiveness of molluscan herbivores was limited to 50 to 100 cm from these refuges. The absence of large herbivorous fish, and the sparse numbers of herbivorous crabs at this site, means that algae can achieve a spatial escape from consumption, and where this occurs competition between producers is important in assemblage development. Mucus appeared to play a limited role, only sometimes stimulating initial stages of unicellular cyanobacteria and macroalgae. With the onset of summer, macroalgae died back, and rock space became available for colonization. Unicellular cyanobacteria developed rapidly but were replaced in all treatments by the encrusting macroalga, Hapalospongidion gelatinosum, which dominated treatments until the end of the experiment. On seasonal, tropical shores processes influencing community structure can, therefore, be temporally variable and their relative importance, even at the same shore level, can change with season.

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Ecological Studies on Some Agarophytes from Veraval Coast (India) I. Effects of Aerial Conditions on the Biomass Dynamics

Cited by 12 publications

References 20 publications

Croissance et capacité reproductive d’<i>Hypnea musciformis</i> (Rhodophyceae, Gigartinale) de la côte atlantique marocaine

Croissance et capacité reproductive d’<i>Hypnea musciformis</i> (Rhodophyceae, Gigartinale) de la côte atlantique marocaine

Variação espaço-temporal de populações de Hypnea musciformis (Rhodophyta, Gigartinales) na baía de Sepetiba e Armação dos Búzios, RJ, Brasil

Primary succession on a seasonal tropical rocky shore: the relative roles of spatial heterogeneity and herbivory

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